But Clancy Mead’s 944 prop runaway had occurred June 18, 1957—more than two weeks after the compliance date had passed. This seems to confirm claims by several Pan Am veterans that maintenance standards had slipped at the airline, which was rapidly losing money on the posh Stratocruiser and had already announced plans to replace the 377s with jets.

The problem with the oil transfer bearing was soon corrected, thanks to subsequent ADs. But had it been fixed before Romance of the Skies took off on its final flight?

The near-half-century that has passed since the loss of 944 has made it possible to rule out some of the theories that had been put forward at the time of the crash. For example, Japanese pathologists in the 1980s—fearful that the high incidence of drunk businessmen falling off their boats and drowning was the handiwork of organized crime—confirmed that excesscarbon monoxide, the forensic discovery that had worried CAB investigators as they first looked for causes of the crash, can be the result of natural decomposition in warm saltwater. But there is still no smoking gun that would allow Ken and me to say we have solved the mystery.

Ocean charts indicate that the resting place of 944 is at a depth within the range of today’s miniature subs. Deep-sea submersibles of the sort that discovered the resting place of the Titanic could almost certainly answer the question of whether Romance of the Skies broke apart from the aerodynamic stresses caused by a dead engine, or whether a disintegrating propeller pierced the cabin and started a fire, also knocking out communications.

But without a Titanic-like expedition, our next best hope lies in finding an audio tape that has become the Holy Grail of our search. Our Pan Am friends have told Ken and me about a tape recording of radio transmissions from aircraft transiting the Pacific that day. The recording, which was entered into evidence at the CAB hearing on 944 back in 1958, seemed to include a last desperate “Mayday” from Romance of the Skies after all. Pilots who had known the airplane’s crew claimed that, upon repeated playbacks, they could hear a faint, garbled message on the tape. Pan Am had appealed for help to Bell Laboratories, which, after analyzing the tape for three months, concluded that it contained no recognizable words.

Thanks to computers and the cold war, however, signal analysis has made giant strides over the past several decades. Digital processors have replaced the oscilloscopes of the 1950s. Recently, experts at the National Transportation Safety Board were able to deduce the cause of a helicopter crash by listening carefully to a recording of the pilot’s frantic radio calls. In the background, almost too faint to be heard, was the telltale sound of a failing gear. When the wreckage was pulled up from the bottom of San Francisco Bay, the NTSB’s hypothesis was confirmed.

The archivist at Lucent Technologies—formerly Bell Labs—says that both Lucent’s copy of the tape and the report done for Pan Am have likely been destroyed. Pan American Airways went out of business in 1991, and the University of Miami now owns its records. The bulk of those—some 1,000 boxes—remains in storage at a former Navy base nearby. That collection is largely unprocessed and is currently off limits to researchers. But it is likely that the maintenance records for 944, Pan Am’s internal investigation of Eugene Crosthwaite, and perhaps even the audio tape are all in that labyrinth of boxes.

The archivist at the University of Miami estimates that it will be at least three years before the Pan Am collection is processed and opened to researchers. NTSB representatives have expressed a willingness to reopen the investigation of Romance of the Skies if new evidence—or, in this case, old evidence that can be reanalyzed by new methods—surfaces.

If the tape is found, what might it reveal—if anything? An explosion? A struggle in the cockpit with a madman? Or the shrill, accelerating scream of a runaway propeller? When those boxes are opened, Ken and I plan to be there.